It is estimated that around 45-60 million American women suffer from sexual disorders at some point in their lives. In comparison, about 30 million men are afflicted with comparable conditions. In both men and women, sexual disorders can be associated with a number of clinical conditions, including diabetes, heart disease, hypertension, multiple sclerosis, and depression. The assessment of the physiology of sexual response is of fundamental importance to research on sexual function and dysfunction. The most widely used approach to the measurement of sexual response involves the assessment of vascular activity in genital tissue. In women, research has largely focused on vaginal blood flow-not primarily because of its central role in female sexual response, but because instruments are readily available and easy to use, unlike current instruments for measurement of clitoral blood flow. However, studies of vaginal blood flow have found no consistent difference between women with and women without sexual disorders. In contrast, recent evidence suggests that clitoral vascular responses are reduced in women with sexual disorders. These results point at the need for new clinical assessment methods for women<s sexual health, though current measurement methods are unreliable, limited, or impractical for general clinical and research use. The proposed project will develop the first practical means of stable sensor placement to enable reliable and practical measurement of clitoral blood flow. The project will also include an evaluation study to simultaneously measure and compare vaginal and clitoral responses. The instrument can be expected to be of fundamental importance to diagnosis, treatment, and research of sexual disorders in women, including basic research on the physiology of sexual function and disorders, clinical investigations of treatments for sexual disorders, and investigations on the side effects of drugs such as antidepressants on sexual health. Due to its ease of use, the clip also has significant potential for therapeutic application in the privacy of a patient<s home, such as for biofeedback, sensate focus, drug treatment, or other medical and behavioral interventions. PUBLIC HEALTH RELEVANCE: Approximately 45-60 million American women suffer from sexual disorders at some point in their lives, but progress in diagnosis and treatment is hindered in part by a lack of valid approaches to the measurement of relevant physiological processes. The proposed project will develop a new instrument that will enable important research on such processes and has the potential to become the method of choice for novel diagnostic and therapeutic procedures.